Hawke's Bay Regional Council is undertaking a biodiversity project with The Conservation Company to survey areas around the region where critically endangered New Zealand native pekapeka tou roa breed.
Principal ecologist for The Conservation Company, Kay Griffiths, said pekapeka could become extinct where management strategies were not put in place, and the work went a long way to supporting their survival.
"We thought bat numbers nationally were stable, but predators like possums, feral cats and rats and a loss of the places they like to live - old trees and lowland forests – has seen their threat status increase to Nationally Critical, the highest ranking," Griffiths said.
"This means without management there is a high likelihood of this native bat becoming extinct."
Griffiths said in the last two years The Conservation Company has led research into long-tailed bat populations in the Tikokino and Ashley Clinton/Makaretu areas funded through DoC Community Fund and supported by HBRC, DoC, WWF Community Fund and many volunteers and landowners.
"Over the last two years we have found two colonies with 40 to 50 breeding females with core roosting area at Puahanui Bush," she said.
"And three colonies in the Ashley Clinton Makaretu area, two with 40 to 50 breeding females and one smaller one with around 20 breeding females."
In the Ashley Clinton/Makaretu area, three colonies have been found.
One colony (dubbed the Makaretu Mob) has its core roosting area around A'Deane's Bush and has around 50 breeding females in the colony.
Another colony has its core roosting area in some bush remnants along the edge of the Tukituki river (the Tukituki Tribe) and has good numbers with more than 40 breeding females. Another smaller colony with its core roosting area was also discovered in Inglis Bush.
Regional council acting manager, catchment services Mark Mitchell said locating where the bats roost around the region would help to identify the priority areas to protect.
"It'll be great to see where potential core roosting areas may be, and once we have that info we can look at the most important areas to protect from predators and habitat loss," Mitchell said.
The research has shown bats like to roost in old native trees such as titoki, rewarewa and matai as well as large exotic trees that have holes in them, like macrocarpa and oak.
"The good thing about bats using old exotic trees is that it opens up a whole lot of our landscape as potential bat roosts, but it's also a bit scary because lots of the older exotic trees around the district are coming to the end of their lives and landowners may want to remove them," Griffiths said.
"Roosts are usually holes in trees but can also be in sheds or under big bits of bark. In some cases in Central HB, people have found them in their garage or woodshed or even in a big sun umbrella or under old covers hanging up in a woolshed.
"I guess with much of their natural habitat gone they are happy to find whatever they can.
"We're asking landowners that need to take down any big old trees to do so out of the bat breeding season, during the summer months – to avoid harming communal bat roosts."